An inactivated bivalent vaccine demonstrated a robust safety profile, with no adverse reactions, mortality, nor impact on weight gain in vaccinated birds during the observation period. Photo: Kemin
An inactivated bivalent vaccine demonstrated a robust safety profile, with no adverse reactions, mortality, nor impact on weight gain in vaccinated birds during the observation period. Photo: Kemin

Dual protection against LPAI H9N2 and NDV Genotype VII

Biologics
Kemin Biologics Company profile
26-09-2025 | |
An inactivated bivalent vaccine demonstrated a robust safety profile, with no adverse reactions, mortality, nor impact on weight gain in vaccinated birds during the observation period. Photo: Kemin
An inactivated bivalent vaccine demonstrated a robust safety profile, with no adverse reactions, mortality, nor impact on weight gain in vaccinated birds during the observation period. Photo: Kemin

An inactivated bivalent vaccine, Mefluvac H9+ND7 0.3, combining avian influenza (AI) H9N2 (2016 strain) and recombinant Newcastle Disease virus (NDV) genotype VII (2017 strain) has been successfully adopted in endemic areas.

Avian influenza H9N2 and NDV genotype VII remain two of the most significant diseases in poultry industry worldwide, causing severe economic losses through mortality and decrease productivity. To address the challenge, an inactivated bivalent vaccine has been adopted. A recent study aimed to assess its safety, immunogenicity, and protective efficacy under controlled conditions.

Method and materials used in the study

A total of 2,000 healthy, antibody-negative chickens aged 3-4 weeks were used for this study. Birds were divided into 2 groups: a vaccinated group of 1,500 chickens receiving a single 0.3 mL dose subcutaneously, and a non-vaccinated control group of 500 chickens. All birds were reared on commercial feed with free access to water, multivitamins before and after vaccination to support immune response.

Prior to the vaccination, blood sampling confirmed negative antibody titers (≤2 log₂) against both NDV and AI H9N2, using the Hemagglutination Inhibition (HI) method. To evaluate the vaccine response serological responses were evaluated at 21, 28 and 60 days post-vaccination. In addition, a challenge test with NDV GVII strain was performed on 200 vaccinated and 100 control chickens at 21 days post-vaccination while the immune response against AI H9N2 was monitored serologically up to 60 days without a challenge test.

Results

Figure 1 – HI antibody profiles against avian influenza H9N2 and Newcastle Disease GVII
Figure 1 – HI antibody profiles against avian influenza H9N2 and Newcastle Disease GVII

The vaccine demonstrated a robust safety profile, with no adverse reactions, mortality, nor impact on weight gain in vaccinated birds during the observation period. Serological results indicated consistent antibody responses. In the vaccinated group, NDV GVII HI titers averaged 6.99 log₂ at 21 days and 5.87 log₂ at 28 days, while AI H9N2 titers reached 7.01 log₂ at 21 days, 6.17 log₂ at 28 days, and 6.07 log₂ at 60 days post vaccination.

In contrast, the control group consistently remained seronegative. The challenge study confirmed the protective efficacy of the vaccine: all 200 vaccinated chickens remained healthy following NDV GVII exposure, while the control group showed 100% mortality.

Conclusion

In the study we found that Mefluvac H9+ND7 0.3 was safe, highly immunogenic, and fully protective against NDV GVII challenge. The vaccine maintained strong antibody titers against both LPAI H9N2 and Newcastle Disease during the observation period. By combining 2 recently isolated strains into a single formulation, this vaccine provides poultry producers with an effective, time-saving solution that reduces labour, minimises bird handling stress, and delivers complete dual protection. These findings highlight the value of Mefluvac H9+ND7 0.3 as a relevant tool for improving poultry health management.

References are available on request.

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Biologics
Kemin Biologics Company profile

At Kemin we empower veterinarians and food producers across the globe to manage the risk against endemic and emerging diseases that compromise profitability and food security worldwide. With a strong awareness of the realities and trends shaping food animal production, we are proud to provide trusted vaccines building immunity for Transboundary Control, Respiratory Integrity, Immunocompetence and Food Safety. Click here to learn more about Kemin Biologics. Click here to learn more about our educational series. 

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Biologics
Kemin Biologics Company profile

At Kemin we empower veterinarians and food producers across the globe to manage the risk against endemic and emerging diseases that compromise profitability and food security worldwide. With a strong awareness of the realities and trends shaping food animal production, we are proud to provide trusted vaccines building immunity for Transboundary Control, Respiratory Integrity, Immunocompetence and Food Safety. Click here to learn more about Kemin Biologics. Click here to learn more about our educational series.